A coupling between the controlling and actuating member and the working head of a portable pipe bending machine

Abstract: A coupling between the piston and cylinder controlling and actuating member and the bending head of a portable pipe bending machine comprising a collar (5) made up of two half collars (5', 5'') with concavities complementary with the side wall of the cylinder (3), which are removably jointed (6, 6') to each other to clamp the cylinder, one of them (5') being rigidly joined (6, 6') to the bending head (1), a coupling which eventually further comprises means for avoiding axial displacement of the collar (5) upon the cylinder (3), particularly a groove (9', 9'') on the collar and a complementary ridge (9) on the cylinder (3).

Description: Field of the Technics The present invention relates to a portable pipe bending apparatus comprising a coupling between a piston and cylinder controlling and actuating member and a bending head. Background of the Invention As is known to those who are skilled in the art, a portable pipe bending machine is made up of two fundamental parts. The first one is a piston actuating member operated with hydraulic, pneumatic or mechanical manual control means possibly assisted by an electric motor. Concretely a piston is dealt with, mounted within an oleodynamic cylinder with a handle control. The second part is the working, that is to say bending or curving head. It comprises a matrix with a groove that receives the pipe to be bent, which matrix is made to advance linearly or it is made to rotate with the pipe in its groove, bending the pipe itself against the rest of two contrast shoulders. The actuation of the matrix is carried out by exploiting the displacements of the aforementioned piston, transforming them into angular advances with suitable mechanisms in the case of a rotating matrix. In the first pipe bending apparatuses the two aforementioned parts, that for controlling and that for bending, were connected in a fixed manner. This, however, was uncomfortable for the operator, in that the controlling handle not always turned out to find itself in a position of easy manoeuvrability, once the bending head positioned for the operation. Then, this drawback was obviated by providing a coupling that were turnable perpendicularly to the axis of the actuating piston, in order to be able to have the handle always in the position of best manoeuvrability for the operator. The turnable coupling known heretofore are ball couplings. They allow a relative rotation of the hydraulic cylinder, whereto the handle is integral, and of the bending head, constrained to the cylinder with a mouthpiece neck interfaced through a ball device. However, ball couplings suffer from the drawback of being not fixable once the optimum angular position of the handle has been found, though affording a certain stability. That is to say, the handle during the bending operation, is subjected to displacements from the optimum position. The object of the present invention is to obviate such a drawback. Such an object is achieved by means of a portable pipe bending apparatus comprising a coupling between a piston and cylinder controlling and actuating member and a bending head, in which the coupling comprises a collar made up of two half collars with concavities complementary to the side wall of the cylinder, the half collars being removably joined with each other by removable joining means to clamp the cylinder, one of the half collars being rigidly joined to the bending head, and in which the piston and cylinder controlling and actuating member, after being rotated about its longitudinal axis, is clamped by the coupling in a desired angular position with respect to the bending head. Advantageously, it is further provided for it that it comprises means for avoiding the axial displacement of the collar upon the cylinder. According to a preferred embodiment, such means for avoiding the axial displacement of the collar upon the cylinder are made up of complementary grooves and ridges provided on the cylinder and on the collar. In a particularly preferred embodiment, a ridge is provided on the cylinder and a groove is provided on the collar, or vice-versa. In a preferred embodiment a reciprocal coupling play is provided between the two aforementioned half collars. According to a preferred embodiment, the removable jointing means between the two half collars are screws. In a particularly preferred embodiment, the screws are mounted across the body of the bending head passing through the half collar jointed to the bending head without gripping it, gripping the other half collar and with their heads abutting against the body of the bending head. According to an embodiment of the present invention, the half collar jointed to the body of the bending head is obtained integrally with the body itself of the bending head. The advantage afforded by the present invention is that the operator can fix the hydraulic cylinder whereto the handle is integral in the desired angular position relative to the bending head and then is able not to take care any more of it, in that the cylinder body and the bending head are integral with each other. Detailed Disclosure of the Preferred Embodiment The present invention will be best understood on the basis of the following disclosure of its preferred embodiment, given only as a matter of example, absolutely not of restriction, with reference to the annexed drawings, wherein: figure 1 is a side view, partially sectioned, of the pipe bending apparatus with the coupling according to the present invention, and figure 2 is a partially sectioned top view of the same. The bending head of the portable pipe bending apparatus is indicated with the general reference number 1. It is exemplified in the so-called fork type, with two groove shoulders intended to operate with a half-moon matrix, it also with a groove, that advances linearly between the two groove shoulders, which are arranged symmetrically to the axis of its displacements, and idling on respective pins. A portion of a shoulder 2 and a support pin 2' are shown in the figures. The cylinder or neck of the controlling and actuating member is indicated with the reference number 3. A piston 4, at the extremity whereof the aforementioned groove matrix (not shown) is fitted with the interface of a spring loaded ball 4' provided on the piston itself, slides in it. The coupling is indicated with the general reference number 5. It comprises a piece 5' provided at the basis of the bending fork, whereto it is rigidly jointed. The piece 5' is endowed with a cavity having a circle sector 7 of almost 180° cross section that couples with the outer wall of the cylinder 3. Moreover, the joint comprises a piece 5'', to be fixed onto the piece 5', it also endowed with a cavity having a circle sector 7' of almost 180° cross section that couples with the outer wall of the cylinder 3. The pieces 5', 5'' are such that jointed to each other form a collar that clamps the cylinder 3 at its interior. The negative deviation from the straight angle of the cross section of the cavity of the two pieces 5', 5'' provides the due play 8 between these. In the preferred embodiment shown in the drawings, the collar is tightened and kept joined to the bending head by means of two screws 6, 6', which are passing through two corresponding bores in the piece 5' and go to grip the piece 5'', the heads abutting against the body of the bending head itself. As the coupling is subjected to high axial stresses during bending operations, complementary axial abutment means are provided on the surfaces 7, 7' of the two pieces 5', 5'' and on the side surface of the cylinder 3. They consist for instance of a transversal ridge 9 on the cylinder 3 and of corresponding grooves 9', 9'' on the surfaces 7, 7'. The present invention has been disclosed and depicted with reference to a specific embodiment thereof, but it is to be expressely understood that changes, additions and/or omissions can be made. For instance, the axial abutment means could also be comprised of a groove on the cylinder and of corresponding ridges on the two parts of the collar, or also of a plurality of grooves and/or ridges on the cylinder and corresponding ridges and/or grooves on the collar.

Claims: A portable pipe bending apparatus comprising a coupling between a piston and cylinder controlling and actuating member (3) and a bending bead (1), characterised in that the coupling comprises a collar (5) made up of two half collars (5', 5'') with concavities complementary to the side wall of the cylinder, the half collars (5', 5'') being removably joined with each other by removable joining means (6, 6') to clamp the cylinder, one of the half collars being rigidly joined to the bending head (1), and in that the piston and cylinder controlling and actuating member (3), after being rotated about its longitudinal axis, is clamped by the coupling in a desired angular position with respect to the bending head (1). The portable pipe bending apparatus according to claim 1, further characterized in that it comprises means (9; 9', 9'') for avoiding the axial displacement of the collar (5) upon the cylinder (3). The portable pipe bending apparatus according to claim 2, wherein the means for avoiding are made up of a complementary groove and ridge provided on the cylinder (3) and on the collar (5). The portable pipe bending apparatus according to claim 3, wherein the ridge (9) is provided on the cylinder (3) and the complementary groove (9', 9'') is provided on the collar (5', 5''). The portable pipe bending apparatus according to claim 3, wherein the groove is provided on the cylinder (3) and the ridge is provided on the collar (5). The portable pipe bending apparatus according to anyone of the preceding claims, wherein a jointing play (8) is provided between the half collars (5', 5''). The portable pipe bending apparatus according to anyone of the preceding claims, wherein the removable joining means between the two half collars (5', 5'') are screws (6, 6'). The portable pipe bending apparatus according to claim 7, wherein the screws (6, 6') pass through the body of the bending head (1), pass through corresponding bores in the half collar which is joined to the body of the bending head and are gripping the other half collar (5''), with the heads of the screws abutting against the body of the bending head (1).

Inventors: CAPORUSSO ALLESSANDRO, CAPORUSSO MARIO, CAPORUSSO, ALLESSANDRO, CAPORUSSO, MARIO
Applicants: CML COSTR MECC LIRI SRL, C.M.L. COSTRUZIONI MECCANICHE LIRI S.R.L.
Application year: 1994
Main classification: B21D7
IPC codes: B21D7